🧪 Strong vs. Weak Acids and Bases: Mastering pH for the DAT

This topic is tested both conceptually and quantitatively. You might be asked to:

• Identify whether a compound is a strong or weak acid/base

• Predict reaction direction

• Solve pH, pOH, or [H⁺] calculations

🔬 Strong vs. Weak Acids and Bases

Type	Ionization in Water	Example Compounds
Strong Acid	100% ionization	HCl, HNO₃, H₂SO₄
Weak Acid	Partial ionization	HF, CH₃COOH, HCN
Strong Base	100% dissociation	NaOH, KOH, Ba(OH)₂
Weak Base	Partial dissociation	NH₃, CH₃NH₂

DAT Tip: Strong acids/bases do not establish equilibrium. Weak ones do—so you’ll often see equilibrium or Ka/Kb problems for weak acids.

📊 pH and pOH Formulas to Know

pH = –log[H⁺]

pOH = –log[OH⁻]

pH + pOH = 14

For strong acids/bases: [H⁺] or [OH⁻] ≈ molarity

For weak acids/bases: Use Ka, Kb, or an ICE table to solve

For strong acids/bases, [H⁺] or [OH⁻] = molarity of solution

For weak acids/bases: Use Ka, Kb, or ICE table to calculate concentrations

🔁 Ka, Kb, and Their Relationship

K_w = K_a × K_b = 1.0 × 10⁻¹⁴

You’ll often be given Ka and asked to find:

• pH

• Kb of the conjugate base

• Whether the conjugate acts as a base or acid

📈 Common DAT Scenarios

• “Which solution has the lowest pH?”

• “What’s the [OH⁻] of a 0.01 M NaOH solution?”

• “What is the conjugate base of H₂CO₃?”

• “Given Ka = 1.8×10⁻⁵, calculate pH of 0.1 M acid”

🧠 Quick pH Estimation Tips

• [H⁺] = 1×10⁻³ → pH ≈ 3

• [OH⁻] = 1×10⁻⁵ → pOH ≈ 5 → pH = 9

• Weak acid = pH between 3–6

• Strong base = pH near 13–14

🎯 Call to Action

Stop memorizing and start visualizing! King of the Curve offers:

• Adaptive quizzes

• Step-by-step pH calculator drills

• Visual guides and daily concept refreshers

👉 Join the Free KOTC Platform

✅ Summary

• Know the difference between strong/weak acids & bases

• Use pH, pOH, and Ka/Kb formulas accurately

• Understand the impact on equilibrium and conjugates

• Be fast at estimating pH and identifying solution types

---

---

Frequently Asked Questions (FAQs)

• How many hours should I study for the MCAT each day?

  Aim for 4-6 focused hours, ensuring you incorporate breaks to avoid burnout.

• What is the best way to handle test anxiety?

  Practice mindfulness techniques, take practice exams under realistic conditions, and maintain a balanced lifestyle.

• How can I stay motivated during the long application process?

  Set short-term goals, seek support from mentors, and reward yourself for small achievements.

• What role does exercise play in MCAT preparation?

  Regular exercise improves focus, reduces stress, and enhances overall mental clarity.

• How does King of the Curve help with MCAT preparation?

  KOTC offers personalized learning tools, gamification features, and adaptive question banks to help students stay on track without burnout.